yeah, I am preparing to make a vacuum tube now! Induction heater , baking furnace, and diffusion pump. Because diffusion pumps are expensive (mainly shipping costs), I am trying to making from aluminum rods with using lathe.

You need getter to improve vacuum. Put a pinch of red phosphorous on filament it will transform to white phosphorous and combine with residual gases. You can also put 2nd lamp in manifold and seal off the pair. Burn 2nd lamp to failure, then seal off the tube to the 1st lamp. 1st lamp will last longer.

Thanks for the tips for improving vacuum!However, red phosphorus is handled as dangerous goods and can not be obtained easily in Japan. I will use titanium or magnesium instead. (And phosphorus has high vapor pressure. and can not be used phosphorus to vacuum tube to be made next)

This is more an educational project than practical, since commercialized incandescent bulbs are cheaper to buy already fabricated than the cost of making your own, just as making your own mechanical clock or even making a simple LED digital watch. Opens up the mind to think what can be done to make it better better or cheaper. Thomas Edison would be proud!

Japan is unlike Europe and the United States, there is no web site like Instructables. and people who doing DIY are decreasing in recent. On the contrary, there are also people who devalue people involved in manufacturing. It is not good... believe that it will get better. :)

I started a project to make a vacuum tube without research. I bought a burner and a fine glass tube at a general shop, first trying to make a light bulb with Nichrome wire. However, at that time I did not know the existence of the dumet wire, I just used a steel wire. Of course it will not work. When I told this shop to the shop owner of a private shop in Akihabara, he introduced a craftsman who had been building a light bulb a while ago. He offered parts for manufacturing bulbs and data on manufacturing. With this process the process has progressed considerably and has reached the present. and my final goal is a vacuum tube. However, it has been more than 50 years since the production of vacuum tubes .... Detailed data on manufacturing has already been lost, and I am still traveling in a blind alley.